Immune responses of adenovirus type-9 infected (tumor-free) male rats against adenovirus type-9 induced mammary fibroadenomas and a chemically induced mammary carcinoma.

Abstract

AbstractLymphocytes from five non‐tumor‐bearing male W/Fu rats infected with human adenovirus type‐9 as newborns or as adults share a common reactivity against rat mammary fibroadenoma target cells and rat mammary carcinoma target cells, as demonstrated by microcytotoxicity tests. Mammary fibroadenomas were induced by adenovirus type‐9 infection of newborn female W/Fu rats, littermates of three of the male lymphocyte donors. The mammary carcinoma target cells were derived from a single rat mammary carcinoma induced by 3,2′‐dimethyl‐4‐amino‐biphenyl (DMABP). Lymphocytes from the male adenovirus type‐9 infected rats were not cytotoxic to normal rat breast epithelial cells, nor to target cells explanted from a polyoma‐virus‐induced sarcoma. Sera from each of five mammary fibroadenoma‐bearing female rats inhibited the cytotoxic effect of lymphocytes from the adenovirus type‐9 infected males against both mammary fibroadenoma and carcinoma target cells. Sera from the female W/Fu rat bearing the DMABP induced mammary carcinoma also inhibited the male lymphocyte cytotoxicity against both fibroadenoma and carcinoma target cells. Serum from rats bearing a polyoma‐virus‐induced sarcoma, though actively blocking in its own system, had no effect on lymphocytes from the adenovirus type‐9 infected males. Anti‐viral antibody response was demonstrated 8 days following adenovirus type‐9 infection of adult males. No anti‐tumor humoral response was demonstrated in either newborn‐infected or adult adenovirus type‐9 infected W/Fu male rats. Sera were checked for cytotoxicity against fibroadenoma and mammary carcinoma target cells in the presence of active homologous complement. No complement‐dependent cytotoxicity was evident. Sera from infected males were admixed to known blocking sera from mammary fibroadenoma‐ and carcinoma‐bearing rats, with no significant abrogation of the blocking effect. These results indicate that, despite the lack of tumor development, infection of male W/Fu rats by adenovirus type‐9 has produced an antigen which is at least partially common to the antigen (s) shared by adenovirus type‐9 induced mammary fibroadenomas and a DMABP induced mammary carcinoma.